Mechanism for handling a bullet melted in a hermetically-sealed furnace

ABSTRACT

A mechanism for handling a billet being melted in a hermetically-sealed furnace in which a rotatable casing is secured on the furnace and accommodates a rotatable drum for winding a loading chain and a roller for guiding the chain through a throat into the space of the furnace and for holding the billet therein.

United States Patent [191 Zlotin et a1.

[ Dec.3, 1974 1 1 MECHANISM FOR HANDLING A BULLET MELTED IN A l-lERMETlCALLY-SEALED;

FURNACE [76] Inventors: Anatoly Vladimirovich Zlotin,

bulvar Lesi Ukrainki, 24b, kv. 77; Jury Mikhailovich Krivoshlykov, bulvar Lesi Ukrainki, 20, kv. 40; Alexei Lavrentievich Tikhonovsky,

ulitsa Vernadskogo, 73, kv.45, all of Kiev, U.S.S.R.

22 Filedfl Jan. 13, 1972 21 App1.No.:217,526

[52] US. Cl 214/18 R [51] Int. Cl. B66c 17/12 [58] Field of Search 266/33 R; 254/195;

214/18 V, 18 R, 18 N [5 6] References Cited UNITED STATES PATENTS Richardson 214/18 V Habighorst 254/195 X Bossi et a1 214/18 R FOREIGN PATENTS OR APPLICATIONS 247,973 1969 U.S.S.R. 277,252 7/1970 U.S.SAR.

Primary ExaminerRichard A. Schacher Assistant Examiner-James W. Miller Attorney, Agent, or FirmHolman & Stern [5 7] ABSTRACT A mechanism for handling a billet being melted in a hermetically-sealed furnace in which a rotatable casing is secured on the furnace and accommodates a totatable drum for winding a loading chain and a roller for guiding the chain through a throat into the space of the furnace and for holding the billet therein.

1 Claim, 2 Drawing Figures PATENTEL 553 3 I974 SHEET 20F 2 IIIIIIIIIIIIIIIIIII A MECHANISM FOR HANDLING A BULLET MELTED IN A I-IERMETlCALLY-SEALED FURNACE BACKGROUND OF THE INVENTION PRIOR ART Known in the art is a mechanism comprising a rod which enters the furnace carrying the billet. This mechanism is provided with drives for reciprocating the billet in a vertical direction and rotating the billet around the longitudinal axis in the process of melting.

At the entrance to the furnace, the rod is provided with an airtight seal which is subjected to heavy wear owing to movement of the rod in three directions.

Additionally, the furnaces used in the above mechanism have to be made higher which involves extra expenditures.

The mechanism for feeding a billet, in remelting process covered by Authors Certificate No. 247973, Cl. 18b, 5/56, USSR, provides for the reduction in height of the furnace owing to the use of a chain or cable.

This mechanism comprises a rotatable airtight casing installed on the furnace and accommodating a drum which is wound with a chain carrying the billet which is secured to the grip of a carriage moving in the guides of a tubular element or throat which provides communication between the furnace and the space of the body of the mechanism.

The tubular element (threat) has a large inside diameter which involves a number of difficulties and fails to ensure reliable sealing of the furnace. For example, the large-diameter surfaces adjoining the hermetic seal must be accurately machined, with this machining calling for considerable amounts of time and skilled labor. Additionally, rotation of the casing with large-diameter friction surfaces calls for the use of powerful motors.

Another mechanism was proposed wherein the object was to reduce the diameter of the vacuum seal (see Authors Certificate No. 277252, Cl. 500, 7/08, USSR). This mechanism incorporates a drum carrying a chain and rigidly secured in the melting furnace. For turning the billet, the chain is connected to a carriage which is coupled with a carrier rotated reversibly by a rod brought out of the sealed furnace to a reversible rotation drive. e

This mechanism has a small diameter vacuum seal but owing to the reversible motion involved, the billet starts swinging and splashing around drops of liquid metal.

Since the drum is mounted above the melting zone of the furnace, it is subjected to'the effect of high temperatures, wherein the lubricating oil of the many moving parts of the mechanism burns out so as to cause these parts to wear down rapidly. Additionally, the metal vapors condense and act as an abrasive material on the chain.

The short life of the mechanism produces serious difficulties in furnace operation and a particularly rapid wear of the seal.

SUMMARY OF THE INVENTION The main object of the invention is to provide a mechanism for feeding a billet into a melting furnace wherein the mechanism has a longer life due to better operating conditions of the seal.

Another object of the invention is to provide a mechanism for improving the sealing of the furnace, i.e. ensuring within it better preservation of the controlled atmosphere. I

Still another object of the invention is to provide a A mechanism whose manufacture requires lower accuracy and smaller amount of skilled labor.

These objects are accomplished by providing a mechanism for handling a billet being melted in a hermeticallysealed furnace said mechanism comprising a rotatable casing installed on the furnace and accommodating a drum with a loading chain wound thereon, the chain carrying the billet and passing through a throat which provides communication between the casing and the furnace wherein, according to the invention, the drum is located to one side of the throat passage and wherein there is a roller secured between the drum and the throat, with said roller intended to guide the billetcarrying end of the chain vertically, along the geometrical axis of the throat whose inside diameter is commensurate with the diameter of the chain.

The various parts of this mechanism are protected against direct thermal effect of the furnace melting zone, the life of the mechanism is longer and its hermetic seal has a comparatively small diameter.

It is desirable that the roller should be so mounted in the casing that the axis thereof is coaxial with the geometrical axis of the throat.

This method of fastening the roller makes it possible to dispense with auxiliary equipment for placing the chain on the drum.

It is desirable that the throat should be secured rigidly to the upper part of the melting furnace. This will provide more favorable temperature conditions for the hermetic seal because it is located farther from the furnace melting zone, its friction surface area is reduced to a minimum and the directions of friction are diminished to one.

BRIEF DESCRIPTION OF THE DRAWINGS DETAILED DESCRIPTION OF A PREFERRED I EMBODIMENT The mechanism for handling a billet 1 (FIG. 1) being melted in a hermetically-sealed furnace 2 comprises a casing 3 with a base in the form of a faceplate 4 mounted on supporting rollers 5 of brackets 6 secured on the upper part of the furnace 2. The casing 3 of the mechanism is rotated by a drive 7 secured rigidly on an immovable support, e.g., furnace 2, interacting with the faceplate 4 of the casing 3. More specifically, the drive is via a bevel gear 7a of the drive 7 and a complemental v bevel gear 7b provided on the perimeter of the faceplate 4. The casing 3 is closed with a cover 8. A space billet-carrying end of the chain 11 along the geometrical axis of the throat 13. I

The inside diameter of the throat 13 is sufficient for the passage of the chain 11, is commensurable with the chain diameter and exceeds it by 0.25-0.5 diameters.

The throat 13 is secured rigidly to the upper part of the furnace 2 and passes through a hole 16 in the faceplate 4 of the casing 3. A hermetic seal 17 and bearings 18 aligning the faceplate 4 at the hole 16 of the faceplate 4 and embracing the upper part of the throat 13 are located to the side of the melting-zone of the furnace 2 and are, therefore, under more favorable temperature conditions.

The drum is located to the side of 'the passage 19 of the throat 13 and is not exposed to direct heat ofthe furnace or to condensation of metal vapors.

This is achieved by using a roller 12 secured by a bearing'assembly 20 in the casing 3, with axle 21 of the roller 12 coinciding with the geometrical axis of the throat l3. l

The billet-carrying end of the chain 11 is provided with a grip 22' for holding the billet 1.

The mechanism for handling the billet during the melting process in a hermetically-sealed furnace operates as follows:

' After the billet 1 has been delivered into the furnace 2 and secured to the grip 22 of the chain 11, the drive of the drum 10 is started and the billet l is lifted vertically to a desired height in the 'melting zone of the furnace 2.

As the billet 1 gradually melts, it is lowered by reversing the rotation drive 15 of the drum 10. The billet 1 is rotated around its longitudinal axis by the drive 7 interacting with the faceplate 4 of the casing 3. The billet is rotated in one direction only, and therefore the molten metal drips from it without splashing occuring.

v The metal vapors produced while the billet l is being melted remain largely in the space 14 of the furnace 2 so that only a small amount of the vapors penetrates into the space 9 ofthe casing 3. This is due to the very small clearance between the chain 11 and thewall of the throat l3.

s The attachment of the roller 12 allows the carrying side of the chain 11 to be kept strictly coaxial with the geometrical axis of the throat 13 and billet 1 during the rotation of the drum 10 and casing 3. Besides, there is no need for any auxiliary devices for consecutive laying of the chain coils on the drum l0.

seal. 17. i

Location of the drum 10 to the side of the passage 19 of the throat 13 eliminates the effect of heat radiation from the melting zone of the furnace 2 and improves the operational conditions of the drum 10 because the latter is not dusted by the deposited metal vapors; in addition, the lubricating oil does not burn out and this improves the working conditions of the friction surfaces.

Introduction of the chain 11 into the space 14 of the furnace 2 through the passage 19 of the throat 13, whose opening is sufficient only for inserting the chain 1 1, makes it possible to use a hermetic seal 17 of comparatively small diameter even when the mechanisms is handling billets 1 weighing many tons. The small diameter hermetic seals 17 possess considerable advantages over those of large-diameter with respect to their durability and simplicityof manufacture and servicing because an increase in the diameter of the hermetic In this mechanism the hermetically-sealed casing'3 ample can be used with a low-power drive because itincorporates a small diameter sea]. I

The coaxial position of the vertical turning axle 21,

relative to the geometrical axis of the carrying side of the chain 11, enables the chain to be placed into the grooves of the drum 10 when the drum 10 is located near the roller 12.

The carrying side of the'chain 11 does not deviate from the preset direction. Additionally, the bearing assembly 20 for-the roller 12 eliminates the need for an auxiliary device for the consecutive laying of the coils of the chain 11 on the drum 10. The space 9 of the casing 3 communicates with the space 14 of the furnace 2 and therefore, the vacuum system of the furnace 2 is sufficientto cause a vacuum to exist in the space 9. What is claimedis: v

1. In a hermetically-sealed electron-beam furnace having a melting zone and an upper part, a mechanism for handling a billet being melted in the furnace, said handling mechanismincluding a casing mounted for rotation relative to the furnace, said casing having an inner space, a'tubular throat providing communication between the inner space of the casing and the interior of the upper part of the furnace, means between the casing and the tubular throat providing a hermetic seal between the casing and the upper part of the furnace, a rotatable drum means mounted within the inner space of the casing toone side of the tubular throat, a loading chain wound on the drum means, drive means operably coupled to the drum means for rotating drum means, a roller means secured within the space of the casing between the drum means and the throat for guiding the loading chain vertically along the geometrical axis of the throat, the inside diameter of the tubular throat being commensurable withthe chain diameter and exceeding the chain diameter by 0.250.5 diameter of the circumscribed circle of the loading chain, and

I the loading chain having one end connected to a billet. 

1. In a hermetically-sealed electron-beam furnace having a melting zone and an upper part, a mechanism for handling a billet being melted in the furnace, said handling mechanism including a casing mounted for rotation relative to the furnace, said casing having an inner space, a tubular throat providing communication between the inner space of the casing and the interior of the upper part of the furnace, means between the casing and the tubular throat providing a hermetic seal between the casing and the upper part of the furnace, a rotatable drum means mounted within the inner space of the casing to one side of the tubular throat, a loading chain wound on the drum means, drive means operably coupled to the drum means for rotating drum means, a roller means secured within the space of the casing between the drum means and the throat for guiding the loading chain vertically along the geometrical axis of the throat, the inside diameter of the tubular throat being commensurable with the chain diameter and exceeding the chain diameter by 0.25-0.5 diameter of the circumscribed circle of the loading chain, and the loading chain having one end connected to a billet. 